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256 THE MODEL RAILROADER for MAY, 1940 ers want to use kits or parts sold by the manufacturers, well and good. By using stock materials the cost has been kept within the reach of every reader. Practically the same kit of tools suffices as Builder's photo of U. S. R. A. light Pacific in use on the Baltimore & Ohio HR. Building a Light Pacific Beginning' a New Locomotive Construction Article, Featuring V.S.R.A. 4·6·2. By M. D. Thornburgh. I N most of the polls conducted by THE MODEL RAILROADER, in search of favored prototypes, the Pacific was voted by readers as the most desirable locomotive to model. This choice is wise. Pacifics are found in all kinds of service: passenger, freight, local freight and even switching! The latter sounds amazing, and I'd have discounted it had I not seen a Pacific, equipped with footboards, sorting 'em out in a yard in Northern Indiana! One of the most widely used (if not the most widely used) light Pacifics is that built to designs compiled by the United States Railroad Administration during the Great War. Hundreds of locomotives were constructed by Lima, Baldwin and others, and locomotives are being built now with the design as a basis but with alterations. The design is standard, so you may letter a model locomotive for almost any Class 1 road and not bring cries of derision from lads who are sticklers for scale. The Baltimore & Ohio RR. has a stud of 30 U. S. R. A. light Pacifics, Classes P-5 and P-5a, numbered 5200 to 5229. Two batches were delivered, 5200 to 5219 by Baldwin Locomotive Works, Philadelphia, and 5220 to 5229 by American Locomotive Works, Schenectady, all constructed in 1919. Both lots are practically alike except for certain characteristics individual to the builders. But in the years since delivery, owing to repairs and rebuilding in the shops along the line, no two locomotives are exactly alike. Nearly all have had the original cast-iron stack removed and replaced by the standard demountable B&O stack, and the headlights remounted at the top of the smoke box where the bells formerly were. The latter were relocated between the sand and steam domes as customary on the B&O. Following my custom, I have endeavored to outline each operation fully from a beginner's standpoint. I hope I have been successful. Old-timers who intend building the model can work directly off the drawings and detour the reading. Views of the locomotive frame under construction. The Pacific is built from stock material without the use of special tools. Only wheel castings are necessary; however, if any read- was listed for the Atlantic and switcher articles, t i.e., a good hand brace, a set of Morse twist drills (Y64" to %"), a 98- cent General Electric soldering iron with large and small bits, a large gasheated soldering bit, several Great Western or Nicholson files (large half-round, large rat tail, small half-round, small rat tail, small square, small flat, small knife, small triangular, a heavy flat bastard) , a pair of dividers, a pair of longnosed pliers, a pair of square-nosed pliers, a pair of diagonal snips, a jewelers' saw, a hack saw, a 2-56 tap, an 0-80 tap, a good pair of metal shears, a vise, a small tack hammer, a small ball'peen hammer, a 6" carpenters' square and a steel rule. For -the benefit of those who have written inquiring where tools may be purchased, all can be obtained at the Pickering Hardware Co., Main near 5th St., Cincinnati, O. This firm conducts a mail order business. The brass listed in the text was bought at the Chase Copper & Brass Co., Opera PL, Cincinnati, for a reasonable sum. However, this company does not handle mail order business in small quantities. The materials can best be gotten from firms who advertise in these pages or from a local hobby shop or brass and copper company. I purchased the sheet of tinplate mentioned later in this series from Pickering Hardware Co. for 26 cents. Two pairs of pilot truck wheels, ''An'' diameter (scale 33"), one pair of spoked trailer wheels, 2%2" diameter (scale 44"), six driving wheels, 11'11.2" (scale 74") or 13%4" (scale 73") in diameter, and four pairs of freight car wheels are necessary. A K: & D. No. 2 motor will furnish sufficient power. Any of the advertisers in this magazine can furnish the motor and the turned wheels and axles. The steel worm and bronze worm gear, 20: 1 ratio, are Boston gears, and are found in Catalog No. 52, page 73, No. G-I018, price 40 cents, and No. "S*," price 70 cents. The alternate wheel dimensions are given because some roads (such as the B&O) use a 74" driver, while others favor a 73" driver. In The Mode! Railroader Cyclopedia the driver dimensions are given as 73". In the course of the switcher series, I received lots of letters complaining about the drawing's discrepancies when compared with those formerly appearing in the magazine. My answer to t ''Building an Atlantic Loco," May-Oct. '38 MR; "Building a U. S. R. A. Switcher," Sept. '39-Feb. '40 MR. " .. 257 the inquiries was this: It must be-remembered changes were made while the locomotives were under construction, and during the year-s of operation even more rebuilding and remodeling has been done. Be that as it may, the drawing shows the locomotive as it is running now. And if any folks wish to model locomotives of another road, I suggest changing the details according to a good photo of the prototype they favor. . A full-sized side elevation of No. 5207, taken from official B&O drawings, to 114" scale, 0 gauge, is shown in Fig. 1. The drawing is dimensioned in feet and inches to permit those who desire to rescale for the smaller gauges. As in the past, and for the benefit of beginners who want to try their hand, the drawing hasn't been messed up with a lot of figures; hence, all parts may be measured off the drawings. Our first problem is construction of the frame (Fig. 2). Two pieces of strip brass, ~"x 0/4" x 8", are necessary. File one end of each square to match both ends perfectly. Test with your square to be certain. Now place both strips together with· squared ends matching, and solder with your heavy gas- heated iron. Get a good fillet of solder around the four sides. Once the strips are soldered, clear the surplus off the squared ends and the top with a smooth file. Don't spoil the squared end, for we'll measure from this. Now start at A and measure the distance to B (Fig. 2). Using the square, scribe a line with a pointed nail at the correct distance. Now you have the length of the frames. Find the distance from A to the leading axle hole, scribe a line the full width, and move to the main axle hole and the rear axle hole. Scribe a line to mark each location. Measure the axle hole centers next. Mark the distance from the top at each end of the strip. Scribe a line the full length of the strip. This gives you every axle hole location. You can also use this line as a guide for marking the frame's shape. As an aid, I've cross-marked the various curve radii in the frame's variations. Punch a hole in the metal with your pointed nail before you scratch the curves with the dividers so they won't slip. Make sure the frame is correct before drilling the axle holes, the next job. The size of the holes depends upon the axle diameters. As I have mentioned before, I prefer %6" axles to 114". The reason: Boston gears have %6" holes, a force fit over %6" drill rod. Whatever axles you use, !kill the holes a bit oversize to let them revolve freely. In drilling axle holes, drill a Vs" pilot hole as a starter. Stick a bit of ~" rod through the hole, Use your hack saw to rough out the frames. Follow up with the jewelers' saw. Finish with files. Give the lines plenty of room; don't overrun them and cut away metal you'll later want when filing. You may always file metal off, but you can't file it back! Keep the strips soldered together until the frame is shaped, then soften the solder in a gas flame to separate them. During the switcher article, many readers made queries about the frame cutouts. While I prefer the frame solid for its added weight, I have outlined the cutouts in Fig. 2. After transferring the shape to the frame, drill and saw with the jewelers' saw, and finish with files. The rear frame is shaped 258 and test with your square. If the hole slants too high or too [ow, tilt your drill in the opposite direction when you turn the final hole. See that your drill is at right angles to the frame at all times. I have found the most satisfactory method to keep the drill at right angles is to let it rest on top of the vise. This acts as a square. THE MODEL RAILROADER from lh" x 1" X 340/64" brass (B to C, Fig. 2) . Draw the center line on the brass. Measure and mark the outline from the top and side elevation, Fig. 2. Rough the shape with yow' hack saw, and true with files. Notice the notches at the head end to accommodate the ends of the plate frame. Actually the bar frames extend back to the end sill; however, it's a job to bend ¥a" strip brass and get it so that it will clear the trailer in the model while rounding sharp curves. Hence, the frames must be taken in, and so the solid frame. Once the frames are cut out, fasten them to- gether. Do this by soldering Va" brass braces (measure their size from Fig. 2) at points shown in the top and side elevations. Make tbe jig (Fig. 3) by screwing a block of wood, 2"x2"x4", to the top of your work table. Shove a piece of glass approximately 6" x 10" against the wood block. Fasten with a few tacks so it won't slide away. Put the frames top down on the glass with ends A against the wood block. Start with the middle brace between the leading and main drivers. Place the brace on the glass in the proper location and squeeze the frames against it, still holding A against the block. Tack the brace with solder to each side. fOT MAY, 1940 Try with your square to ascertain whether the frames are square. If so, solder the leading frame brace at the cylinder saddle permanently. Finally, solder the rear frame to B. As an added precaution, drill a couple of holes on each side of the frame, tap 2-56, and thread in screws. Hold your iron against the frame to sweatsolder the screws. Do all the frame soldering with your heavy iron. Some may wish to spring the axles. If you do, the sketch in Fig. 4, I believe, is self-explanatory. I don't recommend springing, but if carried out, don't spring the rear axle where the gears are fixed . Experiments will be necessary to discover the spring tension. I think music wire (violin or guitar strings), twisted around a drill in the band brace, will answer the purpose. Now that the frames are fastened, find the length of the pilot beam (Figs. 2 and 5). Saw it [rom a length of %0" x %" brass strip. Notice that the ends are %e" high, and that they curve down to the full 3,\," width (Fig. 5). To mortise the frame into the beam, file slots inside the beam. Then drill ]A6" holes at the positions shown in Figs. 5 and 6 to contain the flagholder stems and cotter pins holding the cutoff lever. Next drill '%0" holes in the beam ends (Fig. 6) and file square to copy the holes in the prototype casting. Round the beam ends as shown in the top elevation (Fig. 2) with files. Now tightly solder the beam to the head end of the frame. Fig. 7 illustrates the coupler pocket. Saw and 9' .. ~ 8·-r r---- F''1wre 4 "I, If." " -1-. ,,~ .".c,. for • ..,. r- S'--t--->t 9'8' 3' -1-'9t £.lVD $/,(,,(, file from a piece of %" x %" brass. The pocket flares out at the bottom where it fits underneath the pilot beam. Simulate the casting sides by soldering 28 gauge brass pieces to the pocket sides. File the slot wide enough to permit the coupler shank to swing freely. Drill and tap 0-80 for the coupler pin. Fashion the front and back of the pocket from 28 gauge brass as given in Fig. 7 a. Punch rivets in the back piece before fixing the assembly to the pilot beam. Details of pilot construction are shown in Fig. 6. Obtain the dimensions from Figs. 1 and 5. Model piece A (Fig. 6) from 1/,",' brass. Cut out the center and bend the standards at right angles (Fig. Ga). Punch one rivet in the top end of each standard and solder to the pilot beam. Carry the strip of 28 gauge brass from one standard to the other (B, Fig. 6). Form the pilot bars from 28 gauge brass strips ~),," wide; solder the top end to B and the other to A. After the 11 bars are placed, solder a tin plat" strip along the lower edge as the drawings illustrate. The pilot steps are %" strips of 28 gauge brass. Bend the step part at right angles in your vise, and solder to the pilot beam. Notice the little step 259 fastened to t he pilot standards. Punch the ri vets before fastening. The cutoff lever is shown in Fig. 6a. Fix it to the pilot beam with cotter pins (modeled from %/' wire flattened with a file on one side) thrust through the holes drilled in the beam. Soften the wire hy heating it before bending the cotter pins with pliers. Shape the pin lift from a bit of 1:V' wire soldered to the cutoff lever. Two flag holders, one on each side of the pilot beam (Figs. 5 and 6a) , are required. Turn with files in the hand brace from 1 /8" rod. Leave stems on both to force into the holes drilled in the beam. Drill a ,/,/' hole inside each flag holder so the front grab iron (%l' wire) fits with the ends soldered in the holes. With the pilot completed, fit the end sill (Fig. 5) . Cut to shape and dimensions shown, from '!-b" flat brass. Place the sill flat on your work bench. Stand the frame rear on top of the sill with the center lines matching. Solder with your heavy iron. As an added precaution, drill and tap 2-56, smear some flux on two 2- 56 screws, thread in and then hold your iron so the solder runs and fastens the screws securely. Fig. 8 contains details of the springing. The large sketch illustrates the springing of the leading wheel. The front shackle is anchored to the frame, and the rear shackle is attached to an equalizing lever riding in a hanger held to the frame. Fig. 2 contains full details of the arrangement, and shows how the rear spring shackle connects with a lever bound to the forward trailer truck spring. In our model this is impossible, due to the sharp curves traversed; consequently, the lever must be shortened and fixed to the rear frame where it is covered by the rear brake hanger. Take the dimensions from Fig. 2. Model the springs from 1/&" brass strips. Make the saw cuts and file notches representing the leaves before heating the strip to bend to the form shown in Fig. 2. Then drill the top leaf ends to clear the inverted T shackle, fastened by a bit of Yd' wire. File the T shackle from lfs" brass and drill to clear an escutcheon pin to fasten to the 28 gauge shackles, which are secured to the equalizing bars and frame with escutcheon pins. The equalizing bars are 1/8" brass cut to dimensions taken from Fig. 2. Now for the pilot truck. Two sketches are shown in Fig. 9. Sketch A illustrates a full-sized top and side elevation. Sketch B demonstrates how the truck is modeled. The frames are 'Is" brass. Get the dimensions from A, Fig. 9. Solder the two 1/8" frames together to drill the slightly oversize holes at the